Skoda Electrical Fault (Shock Horror!)

[securespark]

Hi

My normally ultra-reliable Octavia Mk I has developed an electrical fault.

The wipers are constantly on, on the low-speed setting. Have also noticed that when the ignition is switched on, the headlight washer jets fire off (with lights on).

This seems odd, because the windscreen washers don't. Normally what happens is when the lights are on & you wash the screen, the headlights get a squirt too.

Obviously there is a fault, but has anyone got a clue as to where?

The car uses CAN bus wiring (signals for more than one piece of equipment are sent down a shared cable).

I thought initially there may be a short in the wiper motor or the column stalk, but now the headlamp washers are going off on start-up, I'm not sure if the fault is in the wiring or the controller.

 

[Spark123]

If you unplug the stalk does it stop?
What year & model?
Not sure if the car uses the CAN for items such as wipers, I'd suspect they will be wired but not 100% sure.

 

[securespark]

Have not unplugged stalk yet. Car is 2002 Octavia Elegance 1.9 TDi 110 Estate.

 

[Spark123]

That is what I would try first, do you have a haynes manual for the car? If not I'll have a peep later to see if I can find a wiring diagram.

 

[^neo^]

I know the mk4 golfs / caddy vans had problems with the wiper stalks, not sure if they use the same design

 

[securespark]

I talked to a customer today who is an auto electrician.

He suggested unplugging the stalk connector too. Also, he said try disconnecting & reconnecting the battery. If it is run on the CAN bus, this might "reboot" the electronics. He told me to look for a relay for the wipers, the contacts may be stuck in the "on" position. If there is no relay, then the wipers almost certainly are on the CAN bus system & will be controlled by the ECU.....

I shall try all these things when I get a moment in daylight & let you know how I get on.

He also said using VAGCOM to interrogate the system may help.

Thanks, guys, much appreciated.

 

[Spark123]

Have located a wiring diagram for an Octavia there are a few different engine models but the diagrams all appear to be the same, no sign of the headlight wipers on them tho .
Looks like the stalk is direct connecs to unit K8 in position 5 or 6 in the facia fuse box no 2 which is below the dash to the right of the steering wheel.
Good news is if this diagram is correct, it has nothing to do with CAN.

 

[^neo^]

I would think it would only go back to the ecu if it has rain sensing wipers

 

[securespark]

Have located a wiring diagram for an Octavia...Looks like the stalk is direct connecs to unit K8...if this diagram is correct, it has nothing to do with CAN.

Great news 123! Thanks a lot for your reasearch! I shall start I think by replacing this relay.

PS. The headlamps have washers only!

 

[securespark]

Have only looked under the lamps of a petrol forecourt. However, the only fusebox I can find is on the end of the dash, accessible when the door is open. This has shed-loads of fuses in, but no relays.

Can't see anything else under the dash, apart from the VAGCOM port. Will look again in daylight, but it's a rare thing for me, daylight & the Octavia to be together at the same time...

 

[^neo^]

Have a look for a couple of clips holding the fusebox in as the relays may be mounted on the back of the fusebox

 

[securespark]

The local Skoda dealer says they're below the steering column...

Interestingly, they claim to sell 1-2 of these relays per week.

Can't find them.

However, we drove to Mam Tor today (with wipers going full-time!), then on the return journey odd things happened. The rear wiper (previously well-behaved) started wiping. Also, the screen & headlight washers operated randomly without any input.

Then, just as suddenly as the wiper fault appeared, it disappeared. We're back to how we were before. Everything operates exactly as it should.

How odd...